JP2011075816A - Endless fixing belt and thermally fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an elastic layer in an edge part of an endless fixing belt from being damaged, and reduce resistance generated between a metal substrate edge and a flange. <P>SOLUTION: The endless fixing belt 1 mounted on a fixing device for fixing an unfixed image on a recording material and rotated in a direction perpendicular to the width direction, includes a metal substrate 2 and an elastic layer 3 disposed on the metal substrate 2. The edge in the width direction of the metal substrate 2 projects outside the elastic layer 3. A first chamfering part 2a is formed at the corner part on the outer periphery side of the edge in the width direction of the metal substrate 2 that projects outside the elastic layer 3. A second chamfering part 2b is formed at the corner part on the inner periphery side of the edge in the width direction of the metal substrate 2 that projects outside the elastic layer 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an endless fixing belt and a heat fixing device used in an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus.

  In recent years, as a fixing device in an image forming apparatus, a belt-type heat fixing device that can shorten the warm-up time has been widely proposed. FIG. 4 shows a configuration example of a belt-type heat fixing device.

  The heat fixing apparatus shown in FIG. 4 includes a ceramic heater 50 as a heating body, a pressure roller 51 as a pressure member, a heat-resistant endless fixing belt 52, and a belt guide 53. The ceramic heater 50 and the pressure roller 51 are disposed to face each other so that a nip portion N is formed between them. In this heat fixing apparatus, the endless fixing belt 52 and the recording material P on which an unfixed image to be fixed is formed and carried are introduced into the nip portion N. Then, the endless fixing belt 52 and the recording material P introduced into the nip portion N are nipped and conveyed by the ceramic heater 50 and the pressure roller 51, and the heat of the ceramic heater 50 passes through the endless fixing belt 52 at the nip portion N. The recording material P is given. As a result, the unfixed image is fixed to the surface of the recording material P by heat and pressure by heat and pressure at the nip portion N.

  Furthermore, a heat fixing device using a metal belt as an endless fixing belt is also known. In this type of heat fixing apparatus, an induction heating method in which a metal belt or a conductive member in the vicinity of the metal belt self-heats is often employed. Specifically, an eddy current due to electromagnetic induction is generated in a metal belt or a conductive member, and heat is generated by Joule heat.

  A heat-resistant resin, metal, or the like can be used for the base material of the endless fixing belt as described above. In particular, when dealing with higher speed and higher durability of the fixing device, it is preferable to use a metal having excellent strength, for example, SUS, nickel, copper, aluminum, or the like as the base material of the endless fixing belt.

  Also, a fixing device using an endless fixing belt having an elastic layer has been proposed in order to prevent image defects after fixing and obtain a high-quality image free from unevenness in print quality such as gloss. By using an endless fixing belt having an elastic layer, the surface of the endless fixing belt easily follows unevenness on the surface of the recording material, unevenness due to the presence or absence of the toner layer, and unevenness of the toner layer itself. As a result, a phenomenon in which a difference in heat applied from the fixing belt between the concave portion and the convex portion is reduced, and a reduction in image resolution due to a difference in toner melting state is prevented.

  By the way, in the heat fixing apparatus as described above, a moving force is generated toward the endless fixing belt due to variations in accuracy of parts such as a pressure roller and a ceramic heater that sandwich and convey the endless fixing belt (form a nip portion). This will be specifically described with reference to FIG. That is, a force acting on the endless fixing belt 52 in the direction (arrow b direction) intersecting the rotation direction of the belt 52 (arrow a direction) is generated. This force is the shifting force. The shifting force is also generated by a temperature distribution in the longitudinal direction of the ceramic heater 50 (FIG. 4).

  Therefore, in order to hold the end portion of the endless fixing belt 52 against the above-mentioned shifting force, the left and right end portions of the endless fixing belt 52 are received by flanges 54 having good heat resistance made of phenol resin or polyimide resin. Has been proposed. That is, it has been proposed to restrict the displacement and deformation of the endless fixing belt 52 due to the above-mentioned shifting force by receiving the left and right ends of the endless fixing belt 52 with the flange 54.

  However, the endless fixing belt 52 is repeatedly driven and stopped while the bending at the nip portion N is repeated and the end surface thereof is in contact with the flange 54. Therefore, the end portion of the endless fixing belt 52 is constantly subjected to a load due to sliding friction with the flange 54. Therefore, the end of the endless fixing belt 52 is bent, wrinkled, cracked, etc., and it is difficult to maintain heat resistance and durability over a long period of time.

  Therefore, for example, Patent Document 1 discloses a measure relating to the problem of preventing cracks in the metal base material of the endless fixing belt. In Patent Document 1, each part of the outer periphery of the cut surface of the metal base material cut to a desired width is chamfered with an abrasive paper disk, and the step generated on the cut surface is removed by grinding without losing all the chamfered shape. It is disclosed that the roughness of the end face is 5 μm or less. According to Patent Document 1, by performing the above-described processing on the end face of the metal base material, generation of cracks from the end face cutting step is prevented.

  Further, Patent Document 2 discloses a flange wear prevention technique that focuses on the rubbing state between the belt and the flange when the endless belt is damaged. Specifically, in Patent Document 2, the length of the elastic layer is made longer than the length of the metal layer at the end of the endless belt having the metal base layer and the elastic layer, and only the elastic layer is arranged at the end. However, it is disclosed that the elastic layer of the endless belt is brought into contact with the flange. According to Patent Document 2, according to the above configuration, the endless belt is in a light contact state with respect to the end flange, and wear of the end flange due to sliding between the endless belt and the end flange is prevented. .

JP 2004-86083 A JP 2006-98931 A

  In recent years, toner image forming apparatuses such as copying machines, printers, facsimiles, and the like have been colorized, and further, high-speed printing has been required to increase the process speed. On the other hand, there is a movement to increase the process speed while securing the fixing property by increasing the nip load.

  In a fixing belt of a heat fixing device mounted on such an image forming apparatus, a heat-resistant rubber elastic layer is often formed on a metal substrate. Here, it is known that the lower the hardness of the rubber elastic layer, the higher the elastic wrapping effect on the toner, and the effect of preventing color image scattering and gloss unevenness can be obtained. Therefore, recently, a rubber elastic layer having a low hardness, such as a hardness of the rubber elastic layer of Hs10 (JIS-A) or less, has been desired in order to further improve the image quality.

  However, when an endless fixing belt provided with a low-hardness rubber elastic layer is attached to a heat fixing device having a high nip load, the following problems may occur.

  That is, since the low elastic rubber elastic layer has low mechanical strength, the shifting force increases due to the high load nip, and the end of the endless fixing belt and the flange rub against each other. May end up. Furthermore, the destructive debris of the rubber elastic layer is sandwiched between the endless fixing belt and the flange, so that the rotation of the endless fixing belt becomes unstable and may stop in the worst case. Breakage may occur at the edges.

  An object of the present invention is to solve at least one of the above problems.

  The endless fixing belt of the present invention is an endless fixing belt that is mounted on a fixing device that fixes an unfixed image on a recording material and is rotated in a direction orthogonal to the width direction. The endless fixing belt has a metal base and an elastic layer laminated on the metal base. The width direction edge part of the metal base material protrudes outside the elastic layer. A first chamfered portion is formed at the outer peripheral surface side corner of the width direction end of the metal base that protrudes outward from the elastic layer. A second chamfered portion is formed at the corner on the inner peripheral surface side of the end in the width direction of the metal base that protrudes outward from the elastic layer.

  The heat fixing device of the present invention includes a fixing belt that is wound around a belt guide and rotated, and a roller that faces the fixing belt. This heat fixing device introduces a recording material carrying an unfixed image in a nip portion between the endless fixing belt and the roller, and heat-fixes the unfixed image on the recording material. The fixing belt is the endless fixing belt of the present invention, and the belt guide is formed with a flange facing the end in the width direction of the endless fixing belt.

  According to the present invention, the elastic layer is prevented from being broken at the end of the endless fixing belt. Further, the resistance generated between the end face of the metal base and the flange is reduced, and the damage of the metal base and the wear of the flange are reduced.

It is sectional drawing which shows an example of embodiment of the endless fixing belt of this invention. It is an enlarged view of the A section shown in FIG. It is a partial expanded sectional view which shows the other example of embodiment of the endless fixing belt of this invention. It is a schematic block diagram which shows an example of a heat fixing apparatus. It is a perspective view with a part omitted showing an example of a belt guide provided with a flange.

  The endless fixing belt of the present invention is formed in a cylindrical shape. In the present invention, the direction orthogonal to the direction in which the endless fixing belt is rotated during use is referred to as a “width direction” to be distinguished from other directions. However, such a distinction is merely a distinction for convenience of explanation.

  Hereinafter, an example of an embodiment of an endless fixing belt of the present invention will be described in detail with reference to the drawings. Here, an example of an embodiment of the endless fixing belt of the present invention will be described by taking the case where it is applied to the heat fixing device shown in FIG. 4 as an example. However, the application target of the endless fixing belt of the present invention is not limited to the heat fixing apparatus shown in FIG.

  FIG. 1 is a diagram (a cross-sectional view in the width direction) showing a part of a cross section when the endless fixing belt 1 according to the present embodiment is cut in parallel with the width direction. FIG. 2 is an enlarged view of a portion A surrounded by a dot-dash line circle in FIG.

  As shown in FIG. 1, an endless fixing belt 1 according to this embodiment includes a belt-shaped metal substrate 2 serving as a base layer, an elastic layer (rubber elastic layer 3) laminated on the metal substrate 2, At least a release layer 4 laminated on the rubber elastic layer 3 is provided. A primer layer (not shown) for increasing the adhesive strength may be provided between the metal substrate 2 and the rubber elastic layer 3 and between the rubber elastic layer 3 and the release layer 4. For the material of the primer layer, a known material such as silicone, epoxy, or polyamideimide may be used, and the thickness is usually about 1 to 10 μm.

  The rubber elastic layer 3 includes at least silicone rubber, and the hardness thereof is Hs8 (JIS-A) or less. Here, the reason why the hardness of the rubber elastic layer 3 is set to Hs8 or less is that, when the hardness is generally Hs8 or less, the shift movement along the longitudinal direction of the fixing belt, which is the subject of the present invention, remarkably appears. However, the hardness of the rubber elastic layer 3 is not limited to Hs8 or less.

  As shown in FIG. 1, the end portions in the width direction of the rubber elastic layer 3 and the release layer 4 do not coincide with the end portions in the same direction of the metal base 2. In FIG. 1, only one of the two end portions in the width direction of the metal substrate 2, the rubber elastic layer 3, and the release layer 4 is shown, but the other end also has the same configuration. .

  That is, the end surfaces of the rubber elastic layer 3 and the release layer 4 are flush with each other. And the end surface of the metal base material 2 is located outside the end surfaces of the rubber elastic layer 3 and the release layer 4 which are flush with each other. In other words, a part of the metal substrate 2 is exposed at both ends in the width direction of the endless fixing belt 1.

  Here, the distance (d) between the end surfaces of the rubber elastic layer 3 and the release layer 4 and the end surface of the metal substrate 2, in other words, the protrusion of the metal substrate 2 with respect to the rubber elastic layer 3 and the release layer 4. The length (d) is desirably 5 mm or more and 20 mm or less.

  Further, as shown most clearly in FIG. 2, the end portion of the metal substrate 2 protruding outward from the rubber elastic layer 3 and the release layer 4 is chamfered. Specifically, the outer peripheral surface side corner of the end portion of the metal substrate 2 is R-chamfered or C-chamfered to form the first chamfered portion 2a. In addition, the inner peripheral surface side corner of the end portion of the metal base 2 is R-chamfered or C-chamfered to form a second chamfer 2b. Here, when the endless fixing belt 1 is mounted on the fixing device shown in FIG. 4, the surface facing the belt guide 53 is an inner peripheral surface, and the surface facing the pressure roller 51 is an outer peripheral surface. Hereinafter, each component of the endless fixing belt 1 will be specifically described.

(Metal base material 2)
The metal substrate 2 needs to have high thermal conductivity and flexibility capable of transmitting thermal energy from a heating source disposed inside the endless fixing belt 1 to the rubber elastic layer 3. From such a viewpoint, it is suitable to form the metal substrate 2 with a metal material such as SUS, nickel alloy, or aluminum. In particular, it is known that the dimensional accuracy of the nickel electroformed belt obtained by the electroforming method is high, and is suitable as the metal substrate 2. In order to reduce the heat capacity and improve the quick start property, the thickness is preferably 100 μm or less, more preferably 15 μm or more and 60 μm or less. When the thickness of the metal substrate 2 is less than 15 μm, the mechanical strength of the endless fixing belt 1 is insufficient, and when it is 60 μm or more, the flexibility of the endless fixing belt 1 may be insufficient.

  As shown in FIG. 2, in this embodiment, chamfered portions 2 a and 2 b are provided at both ends in the width direction of the metal base 2. In FIG. 2, one of the two width direction end portions of the metal base 2 is illustrated in an enlarged manner, but the other end portion in the width direction has the same configuration.

The first chamfered portion 2a is a point X within a range of, for example, 1 to 10 μm in a direction parallel to the outer peripheral surface from the virtual vertex X when assuming that the outer peripheral surface side corner of the metal base end is a right angle. ₁ is a curved surface that connects ₁ and a point X ₂ within a range of 1 to 10 μm in a direction perpendicular to the outer peripheral surface from the virtual vertex X. The second chamfered portion 2b is within a range of, for example, 1 to 10 μm in a direction parallel to the inner peripheral surface from the virtual vertex Y when assuming that the inner peripheral surface side corner of the metal base end is a right angle. a point Y _1, is a curved surface that connects the point Y ₂ on the inner peripheral surface in the range of 1~10μm in a direction perpendicular to the imaginary vertex Y. However, the curvature of the curved surface may or may not be constant.

Further, as shown in FIG. 3, the first chamfered portion 2a, the point X ₁ and the point X ₂ may be linearly connecting plane. The second chamfered portion 2b, the point Y ₁ and the point Y ₂ may be linearly connecting plane.

In any case, the resistance generated between the endless fixing belt 1 and the flange 54 (FIG. 5) by forming the chamfered portions 2 a and 2 b having the shapes as described above at both ends in the width direction of the metal base 2. And the wear of the flange 54 is reduced. When the distance between the virtual vertex X and the point X ₁ or X ₂ is less than 1 μm, it is possible to gradually reduce the resistance generated between the outer peripheral surface side corner of the endless fixing belt 1 and the flange 54. It becomes difficult. Similarly, when the distance between the virtual vertex Y and the point Y ₁ or Y ₂ is less than 1 μm, the resistance generated between the inner peripheral surface side corner of the endless fixing belt 1 and the flange 54 can be reduced. It becomes difficult gradually.

On the other hand, when the distance between the virtual vertex X and the point X ₁ or X ₂ is 10 μm or more, it takes time to form the chamfered portion 2a, which is not practical. Similarly, when the distance between the virtual vertex Y and the point Y ₁ or Y ₂ is 10 μm or more, it takes time to form the chamfered portion 2b, which is not desirable.

  As a method of forming the chamfered portions 2a and 2b, for example, a method of immersing the end portion of the endless fixing belt 1 in an etching solution can be cited. In addition, it is desirable to polish the end surface of the metal substrate 2 with sandpaper or the like in advance to reduce the unevenness of the end as much as possible.

  As the etchant, a known commercially available etchant or the like may be used. As an example, when the chamfered portions 2a and 2b are formed at the end of the metal base 2 made of nickel or a nickel alloy metal material, Melstrip HN-841 (Meltex Co., Ltd.), Melstrip N- A solution such as 950 (Meltex) can be used.

Note that the shape of the chamfered portions 2a and 2b can be controlled by adjusting the concentration of the etching solution, the etching time, the solution temperature, and the like to desired conditions.
(Rubber elastic layer 3)
The rubber elastic layer 3 is formed from a rubber elastic body containing a silicone material of Hs8 (JIS-A) or less. By providing the rubber elastic layer 3 having a low hardness, heat transfer is ensured by covering the heated image in the nip portion N (FIG. 4), and the followability of the surface of the release layer 4 to the surface of the unfixed image. And more efficiently transfer heat.

  In this embodiment, the rubber elastic layer 3 is not formed to both ends in the width direction of the endless fixing belt 1, and the metal substrate 2 is exposed in an area of about 2 to 6% in the width direction from the end of the endless fixing belt 1. To form. By forming the rubber elastic layer 3 in the region shown in the present embodiment, the rubber elastic layer 3 does not rub against the flange (FIG. 5) when the endless fixing belt 1 rotates. Therefore, even when a low-hardness rubber elastic material with low mechanical strength is used, it is possible to prevent the rubber elastic layer 3 from being broken.

  As the material of the rubber elastic layer 3, a material having a hardness of Hs8 (JIS-A) or less, good heat resistance and good thermal conductivity is preferably used, and silicone rubber is particularly preferably used.

  Examples of the silicone rubber used for the rubber elastic layer 3 include polydimethylsiloxane, polymethyltrifluoropropylsiloxane, polymethylvinylsiloxane, and polytrifluoropropylvinylsiloxane. Furthermore, polymethylphenylsiloxane, polyphenylvinylsiloxane, copolymers of these polysiloxanes and the like are also exemplified.

  In addition, you may make the rubber elastic layer 3 contain a reinforcing filler as needed. Examples of the reinforcing filler include dry silica and wet silica. If necessary, calcium rubber, quartz powder, zirconium silicate, clay (aluminum silicate), talc (hydrous magnesium silicate), alumina (aluminum oxide), bengara (iron oxide), etc. are contained in the rubber elastic layer 3. Also good.

  The thickness of the rubber elastic layer 3 is preferably 10 to 1000 μm, particularly preferably 50 to 500 μm. When printing a color image, a solid image is formed over a large area on a recording material, particularly in a photographic image. In this case, if the heating surface (release layer 4) cannot follow the unevenness of the recording material or the toner layer, heating unevenness occurs, and gloss unevenness occurs in the image where the heat transfer amount is large and small. That is, the glossiness is high at the portion where the heat transfer amount is large, and the glossiness is low at the portion where the heat transfer amount is small. If the rubber elastic layer 3 is too thin, the unevenness of the image gloss may occur due to failure to follow the unevenness of the recording material or the toner layer. On the other hand, if the rubber elastic layer 3 is too thick, the thermal resistance of the rubber elastic layer 3 increases and it may be difficult to realize a quick start.

  The thermal conductivity λ of the rubber elastic layer 3 is preferably 0.4 (W / m · k) or more, more preferably 0.6 (W / m · k) or more, and more preferably 2.5 (W / m · k). k) or less, and particularly preferably 2.0 (W / m · k) or less. If the thermal conductivity λ is too small, the thermal resistance may increase and the temperature rise in the surface layer (release layer 4) of the fixing belt 1 may be delayed. If the thermal conductivity λ is too large, the hardness may increase or the compression set may deteriorate.

Such a rubber elastic layer 3 is a known method, for example, a method in which a material such as liquid silicone rubber is coated on the metal substrate 2 with a uniform thickness by means of a blade coating method, a ring coating method or the like, and is heated and cured. Can be formed. It can also be formed by a method of injecting a material such as liquid silicone rubber into a mold and vulcanizing and curing, a method of vulcanizing and curing after extrusion molding, a method of vulcanizing and curing after injection molding, or the like.
(Release layer 4)
The release layer 4 is formed so as to cover the entire surface of the rubber elastic layer 3. The material of the release layer 4 is not particularly limited, and a material having good release properties and heat resistance may be selected, and PFA is particularly preferable. Of course, fluorine resins such as PFA (tetrafluoroethylene / perfluoroalkyl ether copolymer), PTFE (polytetrafluoroethylene), and FEP (tetrafluoroethylene / hexafluoropropylene copolymer) can also be selected. Silicone resin, fluorosilicone rubber, fluororubber, silicone rubber and the like can also be selected. In addition, you may make the release layer 4 contain 10 mass% or less of conductive agents, such as carbon and a tin oxide, in the release layer 4 as needed.

  The thickness of the release layer 4 is preferably about 1 to 100 μm. If the release layer 4 is too thin, a portion having poor film releasability may be formed due to uneven film thickness, or durability may be insufficient. If the release layer 4 is too thick, heat conduction may be deteriorated. In particular, in the case of a resin release layer, the hardness becomes high and the effect of the rubber elastic layer 3 may be lost.

  Such a release layer 4 is a known method, for example, in the case of a fluororesin system, a method of coating, drying and baking a dispersion of fluororesin powder, or a method of coating and bonding a tube in advance. May be formed.

Example 1
Hereinafter, the present invention will be described more specifically with reference to examples. However, this invention is not restrict | limited at all by these Examples.

  A nickel electroformed endless belt (hereinafter referred to as “endless belt”) having a width of 250 mm, an inner diameter of 34 mm, and a thickness of 40 μm was prepared as the metal substrate 2 shown in FIG.

  Polishing processing was performed on both end portions of the endless belt using No. 2000 sandpaper to remove unevenness at the end portions.

Thereafter, both end portions in the width direction of the endless belt were chamfered by etching, and chamfered portions corresponding to the chamfered portions 2a and 2b shown in FIG. Specifically, etching was performed by immersing the endless belt in an etching solution (Melstrip HN-841 (Meltex)) and adjusting the etching time. In this example, chamfering was performed so that the distance corresponding to the distance between the virtual vertex X and the points X ₁ and X ₂ shown in FIG. 2 was 1 μm. Further, chamfering was performed so that the distance corresponding to the distance between the virtual vertex Y and the points Y ₁ and Y ₂ shown in FIG. 2 was 1 μm. In addition, when the shape of the chamfered portion was observed with a SEM (scanning electron microscope) after chamfering, it was confirmed that each of the above distances was a C plane of 1 μm.

  Next, a primer (manufactured by Toray Dow Corning Co., Ltd.) is applied to a region having a width of 230 mm, excluding a region having a width of 10 mm from both end faces in the width direction of the endless belt, and dried at 200 ° C. for 30 minutes to form a primer layer having a thickness of 5 μm. Formed.

  Next, a silicone rubber raw material composition (manufactured by Toray Dow Corning Co., Ltd.) having a hardness of Hs5 (JIS-A) is kneaded, and the silicone rubber raw material composition is applied onto the primer layer using a ring coat method. An elastic layer corresponding to the rubber elastic layer 3 shown in FIG. 1 was formed. Further, in the heat curing step, the coated surface was heated to approximately 200 ° C. with a near infrared lamp arranged substantially parallel to the unauthorized belt, and heat cured for 30 minutes.

  Next, after applying a primer (manufactured by Toray Dow Corning) on the elastic layer, a PFA tube (manufactured by Kurabo Industries) having a thickness of 30 μm is laminated and placed in a 200 ° C. hot air circulating furnace for 10 minutes. Thus, a release layer corresponding to the release layer 4 shown in FIG. 1 was formed.

  The endless fixing belt produced in this way was mounted on a heat fixing apparatus as shown in FIG. 4, and the following idling test was performed. Specifically, it was wound around a belt guide 52 shown in FIG. The results are shown in Table 1.

(Example 2)
As the metal substrate 2 shown in FIG. 1, a nickel electroformed endless belt (hereinafter referred to as “endless belt”) having a width of 250 mm, an inner diameter of 34 mm, and a thickness of 40 μm was prepared.

  Polishing was performed on both end portions in the width direction of the endless belt using No. 2000 sandpaper to remove unevenness at the end portions.

Thereafter, both ends in the width direction of the endless belt were rounded by etching, and chamfered portions corresponding to the chamfered portions 2a and 2b shown in FIG. 2 were formed at both ends in the width direction of the endless belt. Specifically, etching was performed by immersing the endless belt in an etching solution (Melstrip HN-841 (Meltex)) and adjusting the etching time. In this example, chamfering was performed so that the distance corresponding to the distance between the virtual vertex X shown in FIG. 2 and the points X ₁ and X ₂ was 5 μm. Further, chamfering was performed so that the distance corresponding to the distance between the virtual vertex Y and the points Y ₁ and Y ₂ shown in FIG. 2 was 5 μm. In addition, when the shape of the chamfered portion was observed with a SEM (scanning electron microscope) after chamfering, it was confirmed that each distance was a curved surface (R surface) of 5 μm.

  Next, a primer (manufactured by Toray Dow Corning Co., Ltd.) is applied to a region having a width of 230 mm, excluding a region having a width of 10 mm from both end faces in the width direction of the endless belt, and dried at 200 ° C. for 30 minutes to form a primer layer having a thickness of 5 μm. Formed.

  Next, a silicone rubber raw material composition (manufactured by Toray Dow Corning Co., Ltd.) having a hardness of Hs5 (JIS-A) is kneaded, and the silicone rubber raw material composition is applied onto the primer layer using a ring coat method. An elastic layer corresponding to the rubber elastic layer 3 shown in FIG. 1 was formed. In the heat curing step, the coated surface was heated to approximately 200 ° C. with a near-infrared lamp arranged substantially parallel to the endless belt, and was heat cured for 30 minutes.

  Next, after applying a primer (manufactured by Toray Dow Corning) on the elastic layer, a PFA tube (manufactured by Kurabo Industries) having a thickness of 30 μm is laminated and placed in a 200 ° C. hot air circulating furnace for 10 minutes. Thus, a release layer corresponding to the release layer 4 shown in FIG. 1 was formed.

  The endless fixing belt produced in this way was attached to a heat fixing device in the same manner as in Example 1, and an idling test was performed. The results are shown in Table 1.

Example 3
As the metal substrate 2 shown in FIG. 1, a nickel electroformed endless belt (hereinafter referred to as “endless belt”) having a width of 250 mm, an inner diameter of 34 mm, and a thickness of 40 μm was prepared.

  Polishing was performed on both end portions in the width direction of the endless belt using No. 2000 sandpaper to remove unevenness at the end portions.

Thereafter, both ends in the width direction of the endless belt were rounded by etching, and chamfered portions corresponding to the chamfered portions 2a and 2b shown in FIG. 2 were formed at both ends in the width direction of the endless belt. Specifically, etching was performed by immersing the endless belt in an etching solution (Melstrip HN-841 (Meltex)) and adjusting the etching time. In this example, chamfering was performed so that the distance corresponding to the distance between the virtual vertex X and the points X ₁ and X ₂ shown in FIG. 2 was 10 μm. Further, chamfering was performed so that the distance corresponding to the distance between the virtual vertex Y and the points Y ₁ and Y ₂ shown in FIG. 2 was 10 μm. In addition, when the shape of the chamfered portion was observed with a SEM (scanning electron microscope) after chamfering, it was confirmed that each of the distances was a curved surface (R surface) of 10 μm.

  Next, a primer (manufactured by Toray Dow Corning Co., Ltd.) is applied to a region having a width of 230 mm, excluding a region having a width of 10 mm from both end faces in the width direction of the endless belt, dried at 200 ° C. for 30 minutes, and a primer layer having a thickness of 5 μm Formed.

  Next, a silicone rubber raw material composition (manufactured by Toray Dow Corning Co., Ltd.) having a hardness of Hs5 (JIS-A) is kneaded, and the silicone rubber raw material composition is applied onto the primer layer using a ring coat method. An elastic layer corresponding to the rubber elastic layer 3 shown in FIG. 1 was formed. In the heat curing step, the coated surface was heated to approximately 200 ° C. with a near-infrared lamp arranged substantially parallel to the endless belt, and was heat cured for 30 minutes.

  Next, after applying a primer (manufactured by Toray Dow Corning) on the elastic layer, a PFA tube (manufactured by Kurabo Industries) having a thickness of 30 μm is laminated and placed in a 200 ° C. hot air circulating furnace for 10 minutes. Thus, a release layer corresponding to the release layer 4 shown in FIG. 1 was formed.

  The fixing belt thus produced was mounted on a heat fixing device in the same manner as in Examples 1 and 2, and an idling test was performed. The results are shown in Table 1.

Example 4
A nickel electroformed endless belt (hereinafter referred to as “endless belt”) having a width of 250 mm, an inner diameter of 34 mm, and a thickness of 40 μm was prepared as a metal substrate.

  Polishing was performed on both end portions in the width direction of the endless belt using No. 2000 sandpaper to remove unevenness at the end portions.

Thereafter, both ends in the width direction of the endless belt were chamfered by etching, and chamfered portions corresponding to the chamfered portions 2a and 2b shown in FIG. 2 were formed at both ends in the width direction of the endless belt. Specifically, etching was performed by immersing the endless belt in an etching solution (Melstrip HN-841 (Meltex)) and adjusting the etching time. In this comparative example, chamfering was performed so that the distance corresponding to the distance between the virtual vertex X and the points X ₁ and X ₂ shown in FIG. 2 was 0.5 μm. Further, chamfering was performed so that the distance corresponding to the distance between the virtual vertex Y and the points Y ₁ and Y ₂ shown in FIG. 2 was 0.5 μm. In addition, when the shape of the chamfered portion was observed with a SEM (scanning electron microscope) after chamfering, it was confirmed that each of the above distances was a C plane of 0.5 μm.

  Next, a primer (manufactured by Toray Dow Corning Co., Ltd.) is applied to a region having a width of 230 mm, excluding a region having a width of 10 mm from both end faces in the width direction of the endless belt, and dried at 200 ° C. for 30 minutes to form a primer layer having a thickness of 5 μm. Formed.

  Next, a silicone rubber raw material composition (manufactured by Toray Dow Corning Co., Ltd.) having a hardness of Hs5 (JIS-A) is kneaded, and the silicone rubber raw material composition is applied onto the primer layer using a ring coat method. An elastic layer was formed. In the heat curing step, the coated surface was heated to approximately 200 ° C. with a near-infrared lamp disposed substantially parallel to the metal substrate, and was heat cured for 30 minutes.

  Next, after applying a primer (manufactured by Toray Dow Corning) on the elastic layer, a PFA tube (manufactured by Kurabo Industries) having a thickness of 30 μm is laminated and placed in a 200 ° C. hot air circulating furnace for 10 minutes. Thus, a release layer was formed.

  The endless fixing belt produced in this way was mounted on a heat fixing apparatus as shown in FIG. 4 in the same manner as in the above examples, and an idling durability test was performed. The results are shown in Table 1.

(Example 5)
A nickel electroformed endless belt (hereinafter referred to as “endless belt”) having a width of 250 mm, an inner diameter of 34 mm, and a thickness of 40 μm was prepared as a metal substrate.

Polishing was performed on both end portions in the width direction of the endless belt using No. 2000 sandpaper, and chamfered portions corresponding to the chamfered portions 2a and 2b shown in FIG. 2 were formed in both end portions in the width direction of the endless belt. When the shape was observed with an SEM (scanning electron microscope), the distance between the virtual vertex X and the points X ₁ and X ₂ shown in FIG. It was confirmed that a C-plane having a distance corresponding to 1 is approximately 0.05 μm. In addition, a C surface having a distance corresponding to the distance between the virtual vertex Y and the points Y ₁ and Y ₂ shown in FIG. confirmed.

  Next, a primer (manufactured by Toray Dow Corning) was applied to the entire width direction of the endless belt and dried at 200 ° C. for 30 minutes to form a primer layer having a thickness of 5 μm.

  Next, a silicone rubber raw material composition (manufactured by Toray Dow Corning) having a hardness of Hs5 (JIS-A) is kneaded, and the silicone rubber raw material composition is applied onto the primer layer using a ring coat method, and elastic. A layer was formed. In the heat curing step, the coated surface was heated to approximately 200 ° C. with a near-infrared lamp arranged substantially parallel to the endless belt, and was heat cured for 30 minutes.

  Next, after applying a primer (manufactured by Toray Dow Corning) on the elastic layer, a 30 μm thick PFA tube (manufactured by Kurabo Industries) is laminated and placed in a 200 ° C. hot air circulating furnace for 10 minutes. A release layer was formed.

  The endless fixing belt thus produced was mounted on a heat fixing device in the same manner as in the above examples, and an idling test was performed. The results are shown in Table 1.

(Idle rotation durability test)
While adjusting the temperature to 220 ° C., the pressure roller was pressed against the endless fixing belt with a predetermined pressure, and the endless fixing belt was driven to rotate by the pressure roller. As the pressure roller, a rubber roller having an outer diameter of 30 mm, in which a 3 mm thick silicone layer was covered with a 30 μm thick PFA tube, was used. In this test, the pressure was 200 N, the fixing nip was 8 mm × 230 mm, and the surface speed of the endless fixing belt was set to 220 mm / sec. The rotation test was carried out using the endless fixing belts according to the respective examples and comparative examples, and the time until the endless fixing belt was broken was defined as the endurance time.
Table 1 shows the results of the idling durability test of each example.

(Paper endurance test)
The endless fixing belt according to each of the above examples is mounted on a heat fixing device as shown in FIG. 4 and mounted on a Canon full color LBP LASER SHOT “LBP-2040”, and a paper passing durability test (continuous 100,000 sheets) is performed. went. The applied pressure was 200 N, the fixing nip was 8 mm × 230 m, the fixing temperature was 200 ° C., and the process speed was 220 mm / sec. Table 1 shows the results of the paper passing durability test.

  From these results, it can be seen that durability is improved by chamfering the end portion of the metal substrate of the endless fixing belt. It can also be seen that the range of Examples 1 to 3 is more desirable.

DESCRIPTION OF SYMBOLS 1 Endless fixing belt 2 Metal base material 2a, 2b Chamfer 3 Rubber elastic layer 4 Release layer

Claims (5)

An endless fixing belt mounted on a fixing device for fixing an unfixed image on a recording material and rotated in a direction perpendicular to the width direction,
A metal substrate and an elastic layer laminated on the metal substrate;
An end in the width direction of the metal substrate protrudes outside the elastic layer,
A first chamfered portion is formed on the outer peripheral surface side corner of the width direction end of the metal base material protruding outward from the elastic layer,
An endless fixing belt, wherein a second chamfered portion is formed at a corner portion on the inner peripheral surface side of the end portion in the width direction of the metal base material protruding outward from the elastic layer.   2. The endless fixing belt according to claim 1, wherein a protrusion length of the metal base with respect to the rubber elastic layer at the end in the width direction is 5 mm or more and 20 mm or less. The first chamfered portion is assumed to be parallel to the outer peripheral surface of the endless fixing belt from the virtual vertex of the outer peripheral surface side corner when assuming that the outer peripheral surface side corner of the metal base is a right angle. The point X ₁ in the range of ₁ to 10 μm is connected to the point X ₂ in the range of 1 to 10 μm in the direction perpendicular to the outer peripheral surface of the endless fixing belt from the virtual vertex of the outer peripheral surface side corner. Curved surface,
The second chamfered portion is parallel to the inner peripheral surface of the endless fixing belt from a virtual vertex of the inner peripheral surface side corner when assuming that the inner peripheral surface side corner of the metal base is a right angle. A point Y ₁ that is in the range of 1 to 10 μm in any direction and a point that is in the range of ₁ to 10 μm in the direction perpendicular to the inner peripheral surface of the endless fixing belt from the virtual vertex of the inner peripheral surface side corner The endless fixing belt according to claim 1, wherein the endless fixing belt is a curved surface connecting Y ₂ . The first chamfered portion is assumed to be parallel to the outer peripheral surface of the endless fixing belt from the virtual vertex of the outer peripheral surface side corner when assuming that the outer peripheral surface side corner of the metal base is a right angle. The point X ₁ in the range of ₁ to 10 μm is connected to the point X ₂ in the range of 1 to 10 μm in the direction perpendicular to the outer peripheral surface of the endless fixing belt from the virtual vertex of the outer peripheral surface side corner. A plane,
The second chamfered portion is parallel to the inner peripheral surface of the endless fixing belt from a virtual vertex of the inner peripheral surface side corner when assuming that the inner peripheral surface side corner of the metal base is a right angle. A point Y ₁ that is in the range of 1 to 10 μm in any direction and a point that is in the range of ₁ to 10 μm in the direction perpendicular to the inner peripheral surface of the endless fixing belt from the virtual vertex of the inner peripheral surface side corner The endless fixing belt according to claim 1, wherein the endless fixing belt is a plane connecting Y ₂ . A heating and fixing device comprising: a fixing belt wound around a belt guide and rotated; and a roller facing the fixing belt and forming a nip portion with the fixing belt,
The fixing belt is an endless fixing belt according to any one of claims 1 to 4,
The heating and fixing apparatus is characterized in that a flange facing the end in the width direction of the endless fixing belt is formed in the belt guide.

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